Suspension type heat-dissipation fan

ABSTRACT

A suspension type heat-dissipation fan includes a frame rotatably supporting an air impeller therein. The frame has an air outlet and is formed with an inner rim defining an opening aligned with the air impeller. In addition, a ring is attached to the rim of the frame and has an inner periphery defining an air inlet of a size smaller than the diameter of the air impeller. This inventive fan increases the pressure of airflow into the air inlet, while enabling the air impeller to be placed into the frame through the opening before assembling the ring to the rim.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a fan and, more particularly, to a suspension type heat-dissipation fan which has an air inlet of a reduced size in order to increase the pressure of airflow into the air inlet.

[0003] 2. Description of Related Art

[0004] Many types of fans are known. FIG. 8 shows a suspension type heat-dissipation fan that includes a frame 80 defining an upper air inlet 81. The frame 80 further has a plurality of downwardly-extending struts 82 supporting a lower hub 83, which is provided with a sleeve 84 for rotatably receiving a spindle 86 of an air impeller 85. When being turned, the air impeller 85 blows on a heat sink 87 to facilitate dissipating heat derived from a heat source.

[0005] However, it has been found that the pressure of airflow into the air inlet 81 is relative low, since the air impeller 85 is placed into the frame 80 just through the air inlet 81 and thus the inlet 81 must has a size larger than the diameter of the impeller 85.

[0006]FIG. 9 shows a conventional blower fan that includes a housing 90 for receiving and rotatably supporting an air impeller 91. The housing 90 is covered with a top plate 92 which defines an air inlet 93 aligned with the air impeller 91. When being turned, the impeller 91 draws air through the air inlet 93 and blows out a current of air from an air outlet 94, so as to blow on a heat source.

[0007] In this conventional fan, the air inlet 93 may have a size smaller than the diameter of the air impeller 91 and so the pressure of airflow into the air inlet 81 is increased, but the air impeller 91 can not be placed into the housing 90 through the air inlet 93. This makes the fan complex in structure and difficult to be manufactured.

OBJECT OF THE INVENTION

[0008] The object of the present invention is to provide a suspension type heat-dissipation fan which can increase the pressure of airflow into an air inlet in a simplified manner.

SUMMARY OF THE INVENTION

[0009] The present invention provides a suspension type heat-dissipation fan comprising a frame rotatably supporting an air impeller therein. The frame has an air outlet and is formed with an inner rim defining an opening aligned with the air impeller. A ring is attached to the rim of the frame and has an inner periphery defining an air inlet of a size smaller than the maximum diameter of said air impeller, so as to increase the pressure of airflow into the air inlet.

[0010] Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is an exploded perspective view of a preferred embodiment of a suspension type heat-dissipation fan in accordance with the present invention;

[0012]FIG. 2 is a top view of the suspension type heat-dissipation fan of FIG. 1;

[0013]FIG. 3 is a cross-sectional view taken along lines 3-3 in FIG. 2;

[0014]FIG. 4 is an enlarged cross-sectional view taken from part 4 in FIG. 3;

[0015]FIG. 5 is an exploded perspective view of an alternative embodiment of the inventive fan;

[0016]FIG. 6 is a top view of the suspension type heat-dissipation fan of FIG. 5;

[0017]FIG. 7 is a cross-sectional view taken along lines 7-7 in FIG. 6;

[0018]FIG. 8 is an exploded perspective view of a conventional suspension type heat-dissipation fan; and

[0019]FIG. 9 is an exploded perspective view of a conventional blower fan.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] Referring to FIG. 1, there is shown a preferred embodiment of a suspension type heat-dissipation fan in accordance with the present invention. The inventive fan includes a frame 1 rotatably supporting an air impeller 12 therein. The frame 1 has an air outlet 14, and is formed with an inner rim 13 that defines an upper opening 11 aligned with the air impeller 12.

[0021] In the inventive fan, a ring 2 is attached to the rim 13 of the frame 1 and has an inner periphery that defines an air inlet of a predetermined size smaller than the diameter of the air impeller 12, as best shown in FIG. 2. The air inlet of such a size increases the pressure of air flow in the inlet when the air impeller 12 is in rotation.

[0022] Referring to FIGS. 2 and 3, the ring 2 has an inclined end surface 21, preferably configured as a curved surface, that slopes towards the air impeller 12 from its radially outer portion to its radially inner portion for the purpose of leading air into the air inlet.

[0023] Referring to FIG. 4, the ring 2 can be attached to the inner rim 13 of the frame 1 in many ways. For example, the ring 2 may have an outer periphery defining an annular groove 22 into which the inner rim 13 can be snapped, thus attaching the ring 2 securely to the rim 13 and hence to the frame 1.

[0024] Referring to FIG. 5, an alternative embodiment of the inventive fan is shown. Now the fan includes a frame 1 adapted to be installed on a hollow base 4.

[0025] The hollow base 4, made of a metal material having excellent thermal conductivity, can be connected to the frame 1 by means of a plurality of screws 41. The base 4 has an upright enclosure 42 defining a plurality of vent ports 43 therein. As illustrated, the enclosure 42 preferably consists of four sidewalls with the vent ports 43 defined in more than one sidewall of the enclosure 42.

[0026] The frame 1 is also provided for rotatably supporting an air impeller 12 therein and is formed with an air outlet 13. However, the frame 1 here has an inner rim 13 stepped so as to define a countersunk opening 11, which has an enlarged top part suitable for receiving a ring 3.

[0027] The ring 3 is attached to the stepper rim 13 of the frame 1. Again, the ring 3 has an inner periphery that defines an air inlet of a size smaller than the maximum diameter of the air impeller 12, as best shown in FIG. 6.

[0028] Referring to FIGS. 6 and 7, the ring 3 is situated in the enlarged top part of the countersunk opening 11, and is attached to the stepped inner rim 13 by means of adhesive. Preferably, the ring 3 has a uniform thickness and combined with the rim 13 to form a common top surface of the frame 1, as shown in FIG. 7, thereby providing the inventive fan with an attractive appearance.

[0029] From the foregoing, it is apparent that this invention has the advantage of increasing the pressure of airflow into the air inlet, as well as allowing the air impeller 12 to be placed into the frame 1 through the opening 11 before assembling the ring 2 or 3 to the rim 13.

[0030] While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims. 

What is claimed is:
 1. A suspension type heat-dissipation fan comprising: a frame rotatably supporting an air impeller therein, said fame having an air outlet and being formed with an inner rim defining an opening aligned with said air impeller; and a ring attached to said rim of said frame, said ring having an inner periphery defining an air inlet of a size smaller than the maximum diameter of said air impeller.
 2. The suspension type heat-dissipation fan as claimed in claim 1, wherein said ring has an outer periphery defining an annular groove, and wherein said inner rim of said frame is adapted to be snapped into said annular groove of said ring.
 3. The suspension type heat-dissipation fan as claimed in claim 1, wherein said inner rim of said frame is stepped so as to define a countersunk opening, and wherein said ring is attached to said inner rim by means of adhesive.
 4. The suspension type heat-dissipation fan as claimed in claim 1, wherein said ring has an inclined end surface sloping towards said air impeller from a radially outer portion thereof to a radially inner portion thereof for leading air into said air inlet.
 5. The suspension type heat-dissipation fan as claimed in claim 4, wherein said inclined end surface of said ring is configured as a curved surface.
 6. The suspension type heat-dissipation fan as claimed in claim 3, wherein said ring has a uniform thickness.
 7. The suspension type heat-dissipation fan as claimed in claim 6, wherein said ring is combined with said rim to form a common top surface of said frame.
 8. The suspension type heat-dissipation fan as claimed in claim 1, wherein said frame is adapted to be installed on a hollow base, and wherein said hollow base has an upright enclosure defining a plurality of vent ports.
 9. The suspension type heat-dissipation fan as claimed in claim 9, wherein said enclosure has four sidewalls, and wherein said vent ports are defined in more than one of said sidewalls of said enclosure. 